In mobile communication systems of the LTE (Long Term Evolution) scheme being developed for standardization in the 3GPP, “CFI (Control Format Indicator)”, “DCI (Downlink Control Information)”, and “HI (HARQ Indicator)” are configured to be transmitted as control information in a downlink.
In this case, the CFI is information indicating an OFDM symbol number, of 14 OFDM symbols within one subframe, which is used in a control channel in a downlink.
Moreover, the DCI is control information (resource assignment information, a modulation method, etc.) necessary to transmit uplink data and downlink data. It is noted that there are two types of DCI, i.e., common DCI covering all mobile stations UE and specific DCI covering a specific mobile station UE (a specific mobile station UE or a mobile station UE in a specific group).
Moreover, the HI is transmission confirmation information (ACK/NACK) for the uplink data.
Further, in the mobile communication system of the LTE scheme, the CFI is configured to be transmitted via PCFICH (Physical Control Format Indicator Channel), the DCI is configured to be transmitted via PDCCH (Physical Downlink Control Channel), and the HI is configured to be transmitted via Physical hybrid-ARQ Indicator Channel.